1. Field of Disclosed Subject Matter
This disclosure relates to systems and methods for implementing an asynchronous buffering module and/or scheme employing an integrated registration function, particularly for in-line printing in an image forming system.
2. Related Art
Most modern, sometimes complex, image forming systems include one or more techniques for image forming on both sides of an image receiving media substrate. These two-sided or duplex printing functions typically include the input of a sheet of image receiving media from an input tray and translation of the sheet of image receiving media, via a first transport path, through a media marking engine that is configured to deposit a marking material on a first surface of the sheet of image receiving media. The image may then be fused, or otherwise fixed, on the first surface of the sheet of image receiving media. With a duplex mode selected in the image forming system, the sheet of image receiving media is not output to an output tray. Rather, the sheet of image receiving media is translated, via a second (duplex) transport path, to a beginning of the first transport path, the second (duplex) transport path including a sheet inversion function or unit that results in the sheet of image receiving media being reintroduced, via the first transport path, through the media marking engine again such that the marking material is deposited on a second surface of the sheet of image receiving media. The sheet of image receiving media may then be passed to, or through, an image fusing/fixing unit to finally finish the images on the first and second surfaces of the sheet of image receiving media, prior to passing the sheet of image receiving media to a post-processing device, or to an output tray.
Regardless of the simplicity or complexity of the two-sided or duplex printing operations, duplexing operations typically significantly reduce the page-per-minute (ppm) throughput of the image forming system. The manipulations of the sheets of image receiving media to cause them to appropriately pass through the single media marking engine twice before ultimately being passed downstream in the process direction account for a significant percentage of the reductions in throughput.
Image forming system designers and manufacturers, driven by the competitive nature of the business and in an effort to meet ever increasing production requirements levied by their customers, have sought solutions to limit the reductions in image receiving media throughput in their devices, particularly in a duplex printing mode. One solution to increase the throughput in duplex image forming operations in an image forming system that is to place two marking engines, each operating in a single-side printing or simplex mode, in series. FIG. 1 illustrates a block diagram of an exemplary configuration of such an image forming system 100. As shown in FIG. 1, an image receiving media input source 110 such as, for example, an input tray is provided. Sheets of image receiving media are pulled from the media input source 110 to begin a duplex image forming operation in the exemplary image forming system 100. A first media marking engine 120 forms, and potentially fixes, an image on a first side of the sheet of image receiving media. A media inversion device (sheet inverter) 130 is located between the first media marking engine 120 and the second media marking engine 140 to invert the sheet of image receiving media. The second media marking engine 140 then forms, and potentially fixes, an image on the second side of the sheet of image receiving media. The sheet of image receiving media may then be passed to a media post-processing device 150 and/or to a media output receptacle 160, such as an output tray.